<script type="text/javascript">

//获取指定form中的所有的<input>对象
function getElements(formId) {
  var form = document.getElementById(formId);
  var elements = new Array();
  var tagElements = form.getElementsByTagName('input');
  for (var j = 0; j < tagElements.length; j++){
     elements.push(tagElements[j]);

  }
  return elements;
}

//获取单个input中的【name,value】数组
function inputSelector(element) {
 if (element.checked)
   return [element.name, element.value];
}

function input(element) {
  switch (element.type.toLowerCase()) {
   case 'submit':
   case 'hidden':
   case 'password':
   case 'text':
    return [element.name, element.value];
   case 'checkbox':
   case 'radio':
    return inputSelector(element);
  }
  return false;
}

//组合URL
function serializeElement(element) {
  var method = element.tagName.toLowerCase();
  var parameter = input(element);

  if (parameter) {
   var key = encodeURIComponent(parameter[0]);
   if (key.length == 0) return;

   if (parameter[1].constructor != Array)
    parameter[1] = [parameter[1]];

   var values = parameter[1];
   var results = [];
   for (var i=0; i<values.length; i++) {
    results.push(key + '=' + encodeURIComponent(values[i]));
   }
   return results.join('&');
  }
 }

//调用方法
function serializeForm(formId) {
  var elements = getElements(formId);
  var queryComponents = new Array();

  for (var i = 0; i < elements.length; i++) {
   var queryComponent = serializeElement(elements[i]);
   if (queryComponent)
    queryComponents.push(queryComponent);
  }

  return queryComponents.join('&');
}

</script>
<body>
<form id="login" name="login" method="post" action="result.jsp">
<input name="user" type="text"/>
<input name="sex" type="radio" value="man"/>
<input name="sex" type="radio" value="woman"/>
interest:<input type="checkbox" name="interest" value="piu">PIU <input type="checkbox" name="interest" value="dss">DSS <input type="checkbox" name="interest" value="ddr">DDR<br>
<input type="hidden" name="from" value="welcome"><br>
<input type="button" name="submit" value="submit" onclick="getFormInfo();">
</form>
</body>


function getFormInfo(){
  var params = serializeForm('login');
  alert(params);
}